[generators] Store the resume mode in the generator object.

src/full-codegen/arm64/full-codegen-arm64.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #if V8_TARGET_ARCH_ARM64
 
 #include "src/ast/scopes.h"
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
 #include "src/codegen.h"
@@ skipping 3733 matching lines @@
   // and suchlike. The implementation changes a little by bleeding_edge so I
   // don't want to spend too much time on it now.
 
   Label suspend, continuation, post_runtime, resume, exception;
 
   __ B(&suspend);
   // TODO(jbramley): This label is bound here because the following code
   // looks at its pos(). Is it possible to do something more efficient here,
   // perhaps using Adr?
   __ Bind(&continuation);
-  // When we arrive here, the stack top is the resume mode and
-  // result_register() holds the input value (the argument given to the
-  // respective resume operation).
+  // When we arrive here, x0 holds the generator object.
   __ RecordGeneratorContinuation();
-  __ Pop(x1);
+  __ Ldr(x1, FieldMemOperand(x0, JSGeneratorObject::kResumeModeOffset));
+  __ Ldr(x0, FieldMemOperand(x0, JSGeneratorObject::kInputOffset));
   STATIC_ASSERT(JSGeneratorObject::kNext < JSGeneratorObject::kReturn);
   STATIC_ASSERT(JSGeneratorObject::kThrow > JSGeneratorObject::kReturn);
   __ Cmp(x1, Operand(Smi::FromInt(JSGeneratorObject::kReturn)));
   __ B(lt, &resume);
   __ Push(result_register());
   __ B(gt, &exception);
   EmitCreateIteratorResult(true);
   EmitUnwindAndReturn();
 
   __ Bind(&exception);
@@ skipping 286 matching lines @@
   }
 
   return INTERRUPT;
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_ARM64